Aggregation behavior of Brij-35/perfluorononanoic acid mixtures

MARÍA FLORENCIA TORRES; PABLO SEBASTIÁN SALES; RITA H. DE ROSSI; MARIANA ADELA FERNÁNDEZ

AMER CHEMICAL SOC

Lugar: Washington; Año: 2010 vol. 26 p. 17858 - 17858

p style="TEXT-INDENT: 36pt; MARGIN: 0cm 0cm 0pt" class="BDAbstract">The mixed system of a non-ionic hydrocarbon surfactant, polyoxyethylene (23) lauryl ether (Brij-35), and a perfluorinated surfactant, perfluorononanoic acid, was investigated by a combination of methods. The critical micellar concentrations (CMC) have been determined over a wide range of sample compositions, by fluorescence and UV-visible spectrophotometry using pyrene and N-(4-nitrophenyl) perfluorononanamide respectively as molecular probes. The values of the CMC obtained were considerably different with the two techniques employed. Measurements of 19F nuclear magnetic resonance chemical shift of the same mixtures showed two breaks in the plots of